Chiari malformation I - condition where the cerebellar tonsils
are displaced out of the skull area into the spinal area, causing compression of
brain tissue and disruption of CSF flow

decompression surgery - general term used for any of several
surgical techniques employed to create more space around a Chiari malformation and
to relieve compression

November 20, 2006 -- It seems like every week, or maybe even every
day, the headlines are announcing some new breakthrough involving stem cells: Stem
cells repair hearts! Stem cells repair spinal injury! And of course each and
every major media piece on stem cells includes the obligatory phrase, "stem
cells hold out the promise of curing diabetes, heart disease, Alzheimer's,
Parkinson's, and spinal cord injury".

Discerning the reality through the hype can be difficult, especially given the
inflamed rhetoric and ethical controversy swirling around the use of embryonic stem
cells. While the short-term promise of stem cells may be exaggerated, and despite
the hype, the reality is that scientists are advancing our understanding of stem
cells every day. And with literally billions of research dollars ready to pour
into the field, researchers around the world are turning their attention to turning
the promise of stem cells into reality.

Why is this important to the Chiari community? Because stem cells, which are
able to become different types of cells, may be one way to undo what is now
permanent damage to the nervous system from syringomyelia. Neural cells, which
make up the brain and spinal cord, naturally do not regenerate very much. This is
why damage to the brain or nervous system, from an injury or disease, generally
does not heal well.

The biggest problem for people with Chiari and syringomyelia after surgery is
often the damage that occurred before there was a diagnosis. The nerve damage can
lead to intractable pain, loss of function, and disability. Since nerve cells
don't repair themselves, stem cells - which can become new nerve cells -
theoretically could help repair the damage.

Given the focus which Christopher Reeve brought to the issue of spinal cord
injuries (SCI), many scientists are researching how stem cells can be used to limit
the damage from, or even repair, spinal injuries. An example of their progress can
be found in a report in the November, 2006 issue of the Journal of Neurosurgery:
Spine by a group from Chiba University in Japan.

The Japanese researchers used stem cells derived from umbilical cord blood to
restore some functionality in spinal injured rats. The group chose umbilical cord
blood as a source of stem cells (these are also known as homopoietic stem cells, or
HSC) because of their wide availability, ease of use, and because they avoid the
ethical issues of embryonic stem cells.

To study the effects of the stem cells, the scientists used a well
established model of spinal cord injury in rats where a weight is dropped onto the
exposed spine. Of interest to the Chiari community is the fact that a crushing, or
bruising injury like this results in the formation of a cyst cavity at the site of
the injury.

Nineteen rats were injured in this fashion and one week later 8 of them were
given an injection of the cord blood stem cells directly into the center of the
injury (the dura was opened for this). The other 11 rats were given an injection
of a control substance also in the center of the injury.

Using a well established locomotion scale, the rats were then assessed at
various points in time after the injury and treatment. On a motion scale ranging
from 0-21, all rats scored a 21 prior to the injury and scored a 0 immediately
following the SCI (see Table 1). However, at the five week point, the rats who
were given the stem cells scored an average of 9.8 versus only 7.2 for the control
group. To relate this to actual functionality, a score of 9.8 means the rats were
able to put some weight on their back legs, while a score of 7.2 means the rats
were not able to put any weight on their back legs.

To further examine the effects of the stem cells, certain rats were euthanized
at the different time points and their spinal tissue examined microscopically. In
this fashion, the researchers were able to determine that the stem cell injections
had actually significantly reduced the size of the cystic cavity associated with
the injury. In other words, the stem cell rats had smaller cavities than the
control rats. Similarly, the rats who received the stem cells had more white
matter - a type of neural tissue - around the injury than the ones who didn't
get the treatment.

Interestingly, when the researchers looked for signs of the injected stem
cells in the spinal tissue they found that while the cells were abundant one week
after the treatment, they were largely gone by 3 weeks, and had completely
disappeared by the 5 week mark. Also, and somewhat of a surprise to the team, they
could find no evidence that the stem cells had actually become neural cells.

The Japanese study is a good example of the current state of stem cell
research, especially as it applies to spinal cord injury. There are indications
that stem cells can be of some benefit, but the gains are not miraculous and
scientists do not completely understand how they work.

While it would seem the goal of completely repairing nerve damage to the
spine is a long way off, it is intriguing that even at this early stage there are
indications that stem cells reduced the size of the cystic cavity. And given the
incredible amount of resources being applied to stem cell research, maybe the
ability to repair damage due to a syrinx will be here sooner rather than later.

-- Rick Labuda

Key Points

The media is full of headlines talking about the promise of stem
cells

It can be difficult to assess what stem cells can really do

Study used stem cells from umbilical cord blood to study
restoration of function in rats after spinal cord injury

Weight was dropped on the exposed spines of rats to cause SCI

1 week after injury, stem cells were injected into center of
injury for some of the rats

Five weeks after injury, these rats had noticeably improved
function in hindlimbs versus control group

Stem cells also reduced the size of the cystic cavity

Still a long way from stem cell type treatments for SCI and
syringomyelia

Table 1
Functional Restoration in Experimental Group vs Control Group (0-21)

Experimental Group

Control Group

Before SCI

21

21

After SCI

0

0

5 wks After SCI

9.8

7.2

Note: Standard Locomotion Scale was used with a max
score of 21; rats were scored by two trained observers

Disclaimer: This publication is intended for informational purposes only and may or may not apply to you. The
editor and publisher are not doctors and are not engaged in providing medical advice. Always consult a qualified professional for medical
care. This publication does not endorse any doctors, procedures, or products.